1. Field of the Invention
This invention relates to a method of decoding optical signals used to establish the authenticity of credit cards, ID cards, drivers licenses and the like, by establishing an automated hologram verification system. To ensure accurate optical signal analysis, the instant invention comprises an optical clock which serves to initialize the optical decoding device. The decoding results in a verification process which accurately identifies the validity of a holographic code.
2. Description of the Prior Art
In the early days of credit cards, banks provided cards indiscriminately, and control of blank cards was lax. Consequently, there was an ample supply of blank credit cards with the banks' names on them which could be used by criminals. Additionally, the lack of security printing of these cards made it easy for criminals to manufacture their own counterfeit cards whenever a supply of genuine cards was not available, and this "business" enriched many.
As the losses to the banks escalated, the banks increasingly sought measures to tighten the issuance of cards to approved customers, and also to increase the security of the design and manufacturing of the card itself. A number of measures were considered, but it was the introduction of a piece of foil bearing a holographically generated diffraction grating upon the front of the card that virtually eliminated what was then the major source of cards for criminals--the counterfeited card. Unfortunately criminals are still left with at least three other major opportunities for fraud.
The first is the use of a stolen or lost card, or the interception of an issued card before it reaches the customer--which can be used until the holder reports it lost or stolen. The second was the use of a "good" account number re-encoded onto an otherwise outdated or lost, but previously valid card. The third is using a valid number (without the card) or a "white" card with magnetic stripe for use in automatic teller machines (ATM) or telephones where the card is not authenticated by a person, but only machine read. Actually, there is a fourth type of fraud about to reassert itself. The Master Card and Visa holograms have been used in the field for eight years. Soon there will be sufficient technology available for someone, somewhere to begin creating acceptable counterfeits. It is again time for the security printer to remain the proverbial one step ahead of the counterfeiter.
Technology can do little at present with respect to fraud of the first type. Although mailed cards may be kept invalid until the customer receives it and activates it by calling the issuing bank with information known only to the customer and the bank. However, the present invention can effectively enhance security against fraud of the second, third and fourth types.
In a typical credit card transaction a sales clerk looks at the card and, if it appears valid, swipes the card in a magnetic reader, such as that disclosed by Chang et al. (U.S. Pat. No. 4,788,420) and incorporated herein by reference. The reader sends the account access identification number back to the authenticating source. If the source responds with approval, a transaction takes place. Eventually the legitimate card holder receives a bill which he/she pays or disavows. If properly disavowed, eventually the bank will have to absorb the loss since the magnetic reader had provided an authentic account access identification number which was accordingly approved. This is what happens in fraud of the first and second types.
The account access identification number written or encoded into the magnetic stripe is very much like the license plate number of a car. There is not a great deal of information on the license plate, nor is there a great deal of information in the magnetic stripe. The really valuable information, the payment history, the maiden name of the customer's mother, etc. is all stored down stream in the bank's information system. Only the credit available is normally reached by enquiry from the field.
Thus the situation is similar to the automobile's license plate--or registration; not too much information is stored in the field, just a method of getting to the information stored in the Department of Motor Vehicle files.
Access to only a small part of the bank's information on a customer (current validity of the card, available credit) is made available to the merchant through the electronic network which is used every time a credit card is swiped or magnetically read by the equipment currently available to read and report a transaction.
While the supply of generally acceptable credit cards for illicit purposes is imperfect and small, it is still relatively easy for the determined criminal to acquire a physically genuine but outdated credit card and alter the magnetic information and also re-emboss the expiration date and names on the front. While the ironing out of the original name and re-embossing is not perfect and, upon close inspection can be determined by those familiar with such fraud, these mundane attempts to defraud are generally successful. Then, when the card is swiped, a credit worthy account is identified and the swipe machine is given a green signal to validate or authenticate the transaction.
In some cases, especially at an ATM the only thing the criminal needs is a blank card with a magnetic tape encoded with a valid magnetically readable account access identification number and the unsuspecting victim's personal identification number (PIN) number. There are also a number of places, telephone kiosks and supermarkets where PIN numbers are not required and clerk verification of the actual card is not done.
There has been a long and valiant attempt to make the magnetic encoding secure and resistant to alteration. Watermark.TM. tape by Thorne-EMI was one such. The development of high oersted tapes by 3M Company and others is another. Both provide some limited enhancement of security in their own ways. But neither has found acceptance in the industry because of the changes to existing procedures each might require.
The Thorne-EMI approach magnetically incorporates a sequential number into the tape while the tape is in the manufacturing process; this can then be read by the magnetic reader. The idea and process was thwarted by the difficulty of manufacturing the tape and by keeping sequential numbering accounted for; and it was generally deemed to be too expensive.
The 3M solution is a solution only to the extent that high coercivity tape requires more powerful encoding equipment than that used to encode 300 oersted tape (the industry standard). To the extent such equipment is harder to obtain, security is at least marginally enhanced. The industry may yet move to high coercivity tape. It would require all Service Bureaus and Banks with their own issuing departments to buy new encoding equipment at least to phase it in over time. This is a heavy investment of equipment by a group with no great incentive to do so and there is no indication such high coercivity encoding equipment would not be available to the criminal element. As stated this is, at best, a marginal move.
In all cases, whatever has been placed within the magnetic reading environment is obtainable to anyone with rudimentary equipment to read the magnetic encoding. What has been lacking in the past, and which this invention solves, is another--unreadable by conventional equipment--level of numbers which can be incorporated into the magnetic stripe in a cost effective way.
An approach to solving the problem already exists with the "batch" number which is printed on most credit cards by the card manufacturer. Most often these are four digit numbers found on all American Express Cards and now upon some Master Cards. If there is some reason to suspect a transaction is fraudulent, then the validity of the card can sometimes be tied into the actual card by telephoning the issuing bank to determine if the batch number is a) genuine and not stolen and b) if the magnetic information pertaining to a particular person on the card was matched to the batch number on the front of the card.
This is an imperfect and laborious way of determining fraud and is only done when the person offering the card appears to be out of character for the transaction--i.e., a teenager in dirty sneakers attempting to use a card to purchase a brand new automobile, or some such off-putting situation.
A further approach is developed by Tominyama et al. in U.S. Pat. No. 4,855,584 of Aug. 8, 1989. They developed a "double" read of the card in question by machine, rather than the above mentioned need to telephone in the data. However, in their approach one needs to hide the "certifying medium" by using a bar code which actually acts like a magnetic stripe. Not only is this improbable in practice but even if one discounted the need to have a "magnetic reader" read the bar code (printed as it is in magnetic ink, column 4, lines 30-39) and printed a bar code viewable only by an IR reader, the determined counterfeiter could decipher the underlying information.
All the criminal needs to do is copy the entire number. The problem is similar to attempting to create a visual security pattern or system which cannot be copied by a color xerox machine. As long as the human eye can see the security pattern so can the color copier. All sorts of attempts have been made to defeat the copier and at this writing all (short of the extremely cumbersome and impractical) have failed. The problem facing the authentication of the credit card is not quite so extreme and it does admit to a novel and very practical solution.
As previously stated, the hologram has been used as an effective security device in many applications such as credit cards, drivers licenses, high security labels and so on. The current credit card automated verification process simply check the information on the magnetic stripe through the phone line. This process does not prevent the counterfeiter from "skimming" a good card and forging cards to sell.
The hologram helped the credit card industry to stop fraud in the mid and late 1980's. The hologram is still one of the most secure devices in printing because it is extremely hard to simulate and counterfeit. Relying on the store clerk to check the hologram visually, however, is unreliable due to human error. To combine the well established magnetic stripe system with an automated hologram verification system is a logical answer for the mounting problem. The instant invention provides a security system which combines the auto-verification of the magnetic information with the holographic information in one swipe through a verification device.